Returns the local part of the supplied QName.
fn:local-name-from-QName( $arg as xs:QName?xs:NCName?If $arg is the empty sequence the function returns the empty sequence.
Otherwise, the function returns an xs:NCName representing the local part of
$arg.
The expression fn:local-name-from-QName(fn:QName("http://www.example.com/example",
"person")) returns "person".